STYLE: prefix indexing, loop spacing in Matrix types

src/OpenFOAM/matrices/LLTMatrix/LLTMatrix.C

src/OpenFOAM/matrices/Matrix/Matrix.C

src/OpenFOAM/matrices/Matrix/MatrixI.H

src/OpenFOAM/matrices/Matrix/MatrixIO.C

src/OpenFOAM/matrices/MatrixBlock/MatrixBlock.C

src/OpenFOAM/matrices/QRMatrix/QRMatrix.C

...AM/matrices/SymmetricSquareMatrix/SymmetricSquareMatrix.C

src/OpenFOAM/matrices/scalarMatrices/scalarMatrices.C

...penFOAM/matrices/scalarMatrices/scalarMatricesTemplates.C